NHL Scoring Model Part 1: Even Strength Goals

This is the first part of many posts that is part of a larger project.  The ultimate goal of this project is to develop a statistical model that will allow me to determine the probability of wins and losses for NHL teams.  I am hesitant to say that I will be able to predict who will win or lose, but rather construct a model for success (i.e. if certain conditions are met, a team is more likely to win).  As hockey fans, we recognize certain events during games that alter the momentum of one team.  The model that I am developing is an attempt to capture important aspects of the game, such as shooting the puck or winning faceoffs.  The data is sourced from war-on-ice.com, and has been organized per team by game spanning from 2005-2014 (totaling over 25,000 rows).  As of right now, I expect to examine several game situations including but not limited to: even strength, power play, shorthanded and 4v4.

The first order of business is examining even strength goals.  I think that everyone can agree that the absence of 5v5 scoring diminishes the ability of a team to be competitive. Along with goals against, scoring goals is one of the most important events that occur during a hockey game.  Recently, the most common explanation for goal scoring is puck possession.  It has been theorized that teams with high puck possession rankings tend to be more successful.  This seems intuitively true, since the team who possesses the puck has more chances at scoring than the team without the puck.  Since there is only one puck on the ice, it is a zero-sum game: whoever doesn’t have the puck cannot score.  The two most common measurements of puck possession are Fenwick and Corsi.  In simple terms, Corsi measures all shots taken, whether they miss the net, blocked, or on net.  Fenwick also measures shots taken, with the exception of those blocked.

In other words:
Corsi = All shots directed toward the net
Fenwick = All shots directed toward the net – Blocked shots

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